Cooper Pair Density of Bi2Sr2CaCu2O8+ x in Atomic scale at 4.2 K.

In pursuit of the elusive mechanism of high- T C superconductors (HTSC), spectroscopic imaging scanning tunneling microscopy (SI-STM) is an indispensable tool for surveying local properties of HTSC. Since a conventional STM utilizes metal tips, which allow the examination of only quasiparticles and not superconducting (SC) pairs, Josephson tunneling using STM has been demonstrated by many authors in the past. An atomically resolved scanning Josephson tunneling microscopy (SJTM), however, was realized only recently on Bi2Sr2CaCu2O8+ x (Bi-2212) below 50 mK and on the Pb(110) surface at 20 mK. Here we report the atomically resolved SJTM on Bi2Sr2CaCu2O8+ x at 4.2 K using Bi-2212 tips created in situ. The I- V characteristics show clear zero bias conductance peaks following Ambegaokar-Baratoff (AB) theory. A gap map was produced for the first time using an atomically resolved Josephson critical current map I C( r) and AB theory. Surprisingly, we found that this new gap map is anticorrelated to the gap map produced by a conventional method relying on the coherence peaks. Quasiparticle resonance due to a single isolated zinc atom impurity was also observed by SJTM, indicating that atomically resolved SJTM was achieved at 4.2 K. Our result provides a starting point for realizing SJTM at even higher temperatures, rendering possible investigation of the existence of SC pairs in HTSC above the T C.

Meta-analysis of the risk of small bowel obstruction following open or laparoscopic colorectal surgery.

BACKGROUND: One of the potential advantages of laparoscopic compared with open colorectal surgery is a reduction in postoperative bowel obstruction events. Early reports support this proposal, but accumulated evidence is lacking. METHODS: A systematic review and meta-analysis was performed of randomized clinical trials and observational studies by searching the PubMed and Cochrane Library databases from 1990 to August 2015. The primary outcomes were early and late postoperative bowel obstruction following laparoscopic and open colorectal surgery. Both ileus and bowel obstruction were defined as a postoperative bowel obstruction. Subgroup and sensitivity analyses were performed, and a random-effects model was used to account for the heterogeneity among the studies. RESULTS: Twenty-four randomized clinical trials and 88 observational studies were included in the meta-analysis; 106 studies reported early outcome and 12 late outcome. Collectively, these studies reported on the outcomes of 148 392 patients, of whom 58 133 had laparoscopic surgery and 90 259 open surgery. Compared with open surgery, laparoscopic surgery was associated with reduced rates of early (odds ratio 0·62, 95 per cent c.i. 0·54 to 0·72; P < 0·001) and late (odds ratio 0·61, 0·41 to 0·92; P = 0·019) postoperative bowel obstruction. Weighted mean values for early postoperative bowel obstruction were 8 (95 per cent c.i. 6 to 10) and 5 (3 to 7) per cent for open and laparoscopic surgery respectively, and for late bowel obstruction were 4 (2 to 6) and 3 (1 to 5) per cent respectively. CONCLUSION: The reduction in postoperative bowel obstruction demonstrates an advantage of laparoscopic surgery in patients with colorectal disease.

Optogenetic activation of intracellular adenosine A2A receptor signaling in the hippocampus is sufficient to trigger CREB phosphorylation and impair memory.

Human and animal studies have converged to suggest that caffeine consumption prevents memory deficits in aging and Alzheimer's disease through the antagonism of adenosine A2A receptors (A2ARs). To test if A2AR activation in the hippocampus is actually sufficient to impair memory function and to begin elucidating the intracellular pathways operated by A2AR, we have developed a chimeric rhodopsin-A2AR protein (optoA2AR), which retains the extracellular and transmembrane domains of rhodopsin (conferring light responsiveness and eliminating adenosine-binding pockets) fused to the intracellular loop of A2AR to confer specific A2AR signaling. The specificity of the optoA2AR signaling was confirmed by light-induced selective enhancement of cAMP and phospho-mitogen-activated protein kinase (p-MAPK) (but not cGMP) levels in human embryonic kidney 293 (HEK293) cells, which was abolished by a point mutation at the C terminal of A2AR. Supporting its physiological relevance, optoA2AR activation and the A2AR agonist CGS21680 produced similar activation of cAMP and p-MAPK signaling in HEK293 cells, of p-MAPK in the nucleus accumbens and of c-Fos/phosphorylated-CREB (p-CREB) in the hippocampus, and similarly enhanced long-term potentiation in the hippocampus. Remarkably, optoA2AR activation triggered a preferential p-CREB signaling in the hippocampus and impaired spatial memory performance, while optoA2AR activation in the nucleus accumbens triggered MAPK signaling and modulated locomotor activity. This shows that the recruitment of intracellular A2AR signaling in the hippocampus is sufficient to trigger memory dysfunction. Furthermore, the demonstration that the biased A2AR signaling and functions depend on intracellular A2AR loops prompts the possibility of targeting the intracellular A2AR-interacting partners to selectively control different neuropsychiatric behaviors.

Reliability and validity of lower extremity computed tomography as a screening tool for osteoporosis.

UNLABELLED: We evaluated the correlation between central bone mineral density (BMD) and peripheral bone attenuation using lower extremity computed tomography (CT). A good correlation was found between lower extremity CT and central BMD suggesting that CT is useful for screening osteoporosis, and that peripheral bone attenuation adequately reflects central BMD. INTRODUCTION: This study aimed to evaluate the reliability and validity of CT as a screening tool for osteoporosis and to estimate the correlation between central BMD and peripheral bone attenuation using lower extremity CT. METHODS: In total, 292 patients who underwent a lower extremity, lumbar spine, or abdomen and pelvic CT scan within a 3-month interval of a dual-energy X-ray absorptiometry (DEXA) examination were included. Following reliability testing, bone attenuation of the L1, L2, L3, L4, femoral head, femoral neck, greater trochanter, distal femur, proximal tibia, distal tibia, and talus was measured by placing a circular region of interest on the central part of each bony region on a coronal CT image. Partial correlation was used to assess the correlation between CT and DEXA after adjusting for age and body mass index. RESULTS: In terms of reliability, all bone attenuation measurements, except the femoral neck, showed good to excellent interobserver reliability (intraclass correlation coefficients, 0.691-0.941). In terms of validity, bone attenuation of the L1 to L4, femoral neck, and greater trochanter on CT showed significant correlations with BMD of each area on DEXA (correlation coefficients, 0.399-0.613). Bone attenuation of the distal tibia and talus on CT showed significant correlations with BMD of all parts on DEXA (correlation coefficients, 0.493-0.581 for distal tibia, 0.396-0.579 for talus). CONCLUSION: Lower extremity CT is a useful screening tool for osteoporosis, and peripheral bone attenuation on lower extremity CT adequately reflects central BMD on DEXA.

Use of permanent marker to deposit a protection layer against FIB damage in TEM specimen preparation.

Permanent marker deposition (PMD), which creates permanent writing on an object with a permanent marker, was investigated as a method to deposit a protection layer against focused ion beam damage. PMD is a simple, fast and cheap process. Further, PMD is excellent in filling in narrow and deep trenches, enabling damage-free observation of high aspect ratio structures with atomic resolution in transmission electron microscopy (TEM). The microstructure, composition, gap filling ability and planarization of the PMD layer were studied using dual beam focused ion beam, transmission electron microscopy, energy dispersive X-ray spectroscopy and electron energy loss spectroscopy. It was found that a PMD layer is basically an amorphous carbon structure, and that such a layer should be at least 65 nm thick to protect a surface against 30 keV focused ion beam damage. We suggest that such a PMD layer can be an excellent protection layer to maintain a pristine sample structure against focused ion beam damage during transmission electron microscopy specimen preparation.

The effect of horse simulator riding on visual analogue scale, body composition and trunk strength in the patients with chronic low back pain.

BACKGROUND: Chronic low back pain (CLBP) is one of the most common musculoskeletal disorders, and thus effective treatments are required. Recently, real horseback riding has been reported to be beneficial for the patients. However, it has some limitations, such as limited approaches and safety issues. OBJECTIVE: The purpose of this study was to investigate the effect of horse simulator riding on back pain, body composition and trunk strength in the patients with CLBP. PARTICIPANTS: Forty-seven men with CLBP (mean age 20.55 ± 1.38 years) were randomly divided into a control group (n = 23) and a horse simulator riding group (n = 24), and visual analogue scale (VAS), body composition and isokinetic trunk strength were measured after 8 weeks for which subjects in a horse simulator riding group had performed the horse simulator exercise (HSE). RESULTS: Horse simulator exercise significantly reduced pain scores of VAS and enhanced isokinetic torques of trunk at 30 and 90°/s. There were also significantly increased muscle mass and decreased fat mass in horse simulator riding group. CONCLUSION: It can be inferred that HSE may be helpful in relief of back pain and recovery of back function through developing trunk strength and balancing the ratio of trunk flexor/extensor muscles.

Infectious complications following allogeneic stem cell transplantation: reduced-intensity vs. myeloablative conditioning regimens.

BACKGROUND: In allogeneic stem cell transplantation (allo-SCT), reduced-intensity conditioning (RIC) is known for producing less regimen-related toxicity. However, whether or not RIC reduces the risk for infection and infection-related mortality (IRM) remains controversial. METHODS: We retrospectively analyzed infectious episodes and IRMs after allo-SCTs by time period and by the intensity of the conditioning regimen (RIC [n = 81] vs. myeloablative conditioning, MAC [n = 150]). RESULTS: The cumulative incidence of any kind of infection was lower in the RIC group through the entire period (72% vs. 87%; P = 0.007). The onset of infections was deferred in the RIC group as compared with the MAC group (P = 0.012). Bacteremia occurred less frequently in the RIC group through the entire period (5% vs. 14%; P = 0.044). However, the incidences of cytomegalovirus reactivation and disease, herpes zoster, virus-associated hemorrhagic cystitis, and invasive fungal infection were not different between the two groups. Furthermore, there was no difference in relapse-free survival and IRM between the two conditioning regimens. CONCLUSION: Careful monitoring and appropriate preventive/therapeutic strategies for infectious complications, comparable to those for allo-SCT recipients with MAC, should also be applied to those with RIC, especially after engraftment.

Atomic-scale interpretation of the quantum oscillations in cuprate superconductors.

Cuprate superconductors display unusual features in bothkspace and real space as the superconductivity is suppressed-a broken Fermi surface, charge density wave, and pseudogap. Contrarily, recent transport measurements on cuprates under high magnetic fields report quantum oscillations (QOs), which imply rather a usual Fermi liquid behavior. To settle the disagreement, we investigated Bi2Sr2CaCu2O8+δunder a magnetic field in an atomic scale. A particle-hole (p-h) asymmetrically dispersing density of states (DOSs) modulation was found at the vortices on a slightly underdoped sample, while on a highly underdoped sample, no trace of the vortex was found even at 13 T. However, a similar p-h asymmetric DOS modulation persisted in almost an entire field of view. From this observation, we infer an alternative explanation of the QO results by providing a unifying picture where the aforementioned seemingly conflicting evidence from angle-resolved photoemission spectroscopy, spectroscopic imaging scanning tunneling microscopy, and magneto-transport measurements can be understood solely in terms of the DOS modulations.

Significance of photodocumentation-associated factors in colonoscopy on the detection rate of colorectal neoplasms.

OBJECTIVE: It is unclear whether photodocumentation is associated with colorectal neoplasm (CRN) detection at colonoscopy, despite its ability to take more images with the development of affordable digital imaging systems. This study aimed to investigate whether photodocumentation-related factors could affect the detection rate of CRNs in healthy subjects. PATIENTS AND METHODS: A total of 2,637 subjects undergoing screening colonoscopy in routine health check-ups at CHA Bundang Medical from January to September 2016 were enrolled in this study. Only the endoscopic image data for observation purposes during colonoscopy withdrawal was used in this analysis. The number of observation images, observation time and the speed of photodocumentation (SPD) defined as the number of observation images per minute were used as quantity measures of photodocumentation. The presence of documented anatomical landmarks such as appendix orifice (AO), ileocecal valve (ICV), anorectal junction was used as quality measures of photodocumentation. RESULTS: Among subject-related factors, the independent factors for CRN detection in the multivariate analysis were age, male sex, waist circumference, and family history of colorectal cancer. In photo-documentation-related factors, SPD [Odds ratio (OR) 0.800; 95% confidence interval (CI), 0.740 to 0.864], observation time over 6 min (OR 1.671; 95% CI, 1.145 to 2.439), clear documentation of appendix orifice (AO) (OR 5.976; 95% CI, 4.548 to 7.852) and ileocecal valve (ICV) (OR 3.826; 95% CI, 2.985 to 4.904), and endoscopists (p < 0.001) were independently significant factors. However, the number of observation images was not associated with the detection of CRNs. CONCLUSIONS: Lower SPD and clear documentation of cecal landmarks might be associated with an increased detection rate of CRNs.

Population-specific spectrum of the F11 mutations in Koreans: evidence for a founder effect.

The aim of this study was to investigate a mutation spectrum of F11 among Korean patients with factor XI (FXI) deficiency and to determine the haplotypes of mutations frequently found in Koreans. Thirteen unrelated patients from non-consanguineous families with FXI deficiency were included in the study. In the mutation analysis, the most frequently found mutations were Q263X (four cases; 31%) and Q226X (three cases; 23%). The frequency of Q263X-bearing haplotype was significantly different between normal and patient groups (p = 0.001), which is consistent with a founder effect of Q263X mutation. Testing for the presence of these two mutations should be the first genetic screening in Korean patients with FXI deficiency.

Acute cytomegalovirus pneumonia and hepatitis presenting during acute HIV retroviral syndrome.

Cytomegalovirus (CMV) disease is a frequent opportunistic infection that usually occurs in the late stages of HIV infection as a result of reactivation of a latent infection. We report a case of a 23-year-old man with acute retroviral syndrome complicated by coexisting CMV pneumonia and CMV hepatitis, which were documented by histopathological examination. His CMV pneumonia and hepatitis were assumed to be primary CMV diseases owing to the absence of CMV IgG antibody. To the best of our knowledge, this is the first case of simultaneous CMV pneumonia and hepatitis occurring as primary CMV diseases during primary HIV infection. This case indicates that invasive CMV diseases such as pneumonia and hepatitis should be considered even in patients with primary HIV infection.

Comparison of lower extremity motor score parameters for patients with motor incomplete spinal cord injury using gait parameters.

STUDY DESIGN: Retrospective investigation using gait analysis and medical records. OBJECTIVE: To evaluate the relationship between ambulatory function improvement and an increase in lower-limb motor scores in persons with motor incomplete spinal cord injury (SCI) and to compare the efficiency of lower extremity motor score (LEMS) and ambulatory motor index (AMI) in representation of ambulatory function improvement using gait analysis. SETTING: SCI Unit, Yonsei Rehabilitation Hospital, Seoul, Korea. METHODS: The gait analysis from 43 patients with SCI (paraplegic, n=22, tetraplegic n=21) were reviewed. The gait analysis data were obtained with Vicon 370 system. The LEMS and AMI were assessed before the gait analysis and the influence of an increase in lower-limb motor scores were investigated with linear parameters of gait analysis. RESULTS: For group including both tetraplegic and paraplegic patients, both AMI and LEMS were statistically correlated with gait speed, step length and negative correlation with double-limb support. However, only LEMS was correlated with cadence. For the paraplegic group, with AMI and LEMS, there were correlation with gait speed, step length and right single-limb support and negative correlation with right double-limb support. However, only LEMS was correlated with left cadence and negative correlation with double-limb support. For the tetraplegic group, only left cadence was statistically correlated with AMI. CONCLUSION: Both AMI and LEMS were useful in terms of providing information for capability of ambulatory function for the paraplegic group. However, for the tetraplegic group, both AMI and LEMS do not provide sufficient information for ambulatory function of the incomplete SCI patients.

Dysphagia in cervical spinal cord injury.

STUDY DESIGN: Retrospective chart review of cervical spinal cord injury patients, who underwent videofluoroscopic swallowing study (VFSS). OBJECTIVES: To evaluate the swallowing function of cervical spinal cord injury patients, analyze the features of dysphagia and investigate their association with the clinical symptoms and signs. SETTING: Spinal Cord Injury Unit, Yonsei Rehabilitation Hospital, Seoul, Korea. METHODS: Retrospective study (1 May 2001-31 May 2008) on inpatients with tetraplegia. All enrolled patients underwent VFSS, and their results were correlated with clinical data including symptoms and signs indicative of dysphagia. RESULTS: A total of 121 cervical spinal cord injury patients (106 male and 16 female patients) were included in this study. Ten patients showed evidence of aspiration on VFSS. Statistical correlation to aspiration was found with age, presence of tracheostomy, and symptoms and signs indicating dysphagia. However, out of the 10 patients with evident aspiration, 2 patients did not show any symptoms or signs indicating aspiration. CONCLUSION: Because of the possibility of silent aspiration, we recommend that physicians treating patients with cervical spinal cord injury should always take the possibility of dysphagia and silent aspiration into consideration, especially in case of previous manifestation of pneumonia, presence of tracheostomy, or presence of signs and symptoms indicating dysphagia.

Early-onset Charcot-Marie-Tooth patients with mitofusin 2 mutations and brain involvement.

Mutations of the mitofusin 2 (MFN2) gene have been reported to be the most common cause of the axonal form of Charcot-Marie-Tooth disease (CMT). A prospective brain MRI study was performed on 18 early-onset CMT patients with MFN2 mutations, and a high frequency (39%) of brain abnormalities was found. Early-onset patients showed multiple scattered or confluent brain lesions that involved gray matter as well as white matter. Patterns of brain involvement in early-onset patients differed from those of late-onset patients and other hereditary peripheral neuropathies. In addition, one CMT patient demonstrated a brain lesion before the development of peripheral neuropathy.

Magnetization distribution in the mixed-phase state of hole-doped manganites.

The effect of 'colossal magnetoresistance' (CMR) in hole-doped manganites--an abnormal decrease of resistivity when a magnetic field is applied--has attracted significant interest from researchers in the past decade. But the underlying mechanism for the CMR phenomenon is not yet fully understood. It has become clear that a phase-separated state, where magnetic and non-magnetic phases coexist, is important, but the detailed magnetic microstructure of this mixed-phase state is so far unclear. Here we use electron microscopy to study the magnetic microstructure and development of ferromagnetic domains in the mixed-phase state of La(1-x)Sr(x)MnO3 (x = 0.54, 0.56). Our measurements show that, in the absence of a magnetic field, the magnetic flux is closed within ferromagnetic regions, indicating a negligible magnetic interaction between separated ferromagnetic domains. However, we also find that the domains start to combine with only very small changes in temperature. We propose that the delicate nature of the magnetic microstructure in the mixed-phase state of hole-doped manganites is responsible for the CMR effect, in which significant conduction paths form between the ferromagnetic domains upon application of a magnetic field.

The Association of Gait Speed and Frontal Lobe among Various Cognitive Domains: The Korean Frailty and Aging Cohort Study (KFACS).

OBJECTIVE: The aim of this study was to determine how gait speed and frontal lobe functionsin community-dwelling older adults in Korea. DESIGN: This was a cross-sectional study. SETTING: The study used data from the Korean Frailty and Aging Cohort Survey (KFACS), a multi-center longitudinal study addressing 10 centers across urban, rural, and suburban communities in Korea, between 2016 and 2017. PARTICIPANTS: A total of 1552 older adults who underwent both gait speed tests and cognitive functions tests during the investigation of the KFACS. MEASUREMENTS: Gait speed was assessed by asking participants to walk from a starting point to a point 4 meters away at a normal gait. Cognitive functions were evaluated using various standardized cognitive functions tests. RESULTS: Gait speed was slower when participants were older or less educated The percentage of women, higher BMI, people with lower incomes, singles, smokers, and drinkers was high in the slower gait group. Also, all cognitive function scores were low and depression score was high in the group with slower walking speed. The slower walking speed showed low physical activity score and high prevalence of hypertension, osteoarthritis and osteoporosis. Among the seven cognitive functions (MMSE, memory, TMT, Recall, Recognition, digit span, and Fab), only TMT showed no significant difference between different gait speed groups. The other six cognitive functions showed higher results in the fastest gait speed group (T3), Participants in middle gait speed group (T2) also showed higher results in five of the seven cognitive function scores as well (Memory, Recall, Recognition, digit span, and Fab). CONCLUSION: In this study, we found correlation between the slower gait speeds and the decrease in cognitive function, and especially the frontal lobe dysfunction was most prominent of all cognitive dysfunctions.

Risk factor analysis of invasive liver abscess caused by the K1 serotype Klebsiella pneumoniae.

The increasing prevalence of Klebsiella pneumoniae liver abscess in Asian countries is attributable to virulent strains of the K1 serotype. We investigated the risk factors for the K1 serotype K. pneumoniae liver abscess. A case-control study was performed using the database of a nationwide study of liver abscess in Korea. Multivariate logistic regression analysis was performed for 78 cases of the K1 serotype K. pneumoniae liver abscess and 81 controls with non-Klebsiella. Diabetes mellitus was the significant risk factor (OR 2.13; 95% CI 1.026 approximately 4.428; P = 0.042) for the K1 serotype K. pneumoniae liver abscess. Biliary disorders had a strong negative association (OR 0.18; 95% CI 0.078 approximately 0.410; P < 0.001). This study suggests that diabetes mellitus is a more significant risk factor for the K1 serotype K. pneumoniae liver abscess than for the non-Klebsiella liver abscess.

Infectious complications associated with alemtuzumab use for allogeneic hematopoietic stem cell transplantation: comparison with anti-thymocyte globulin.

OBJECTIVES: To evaluate the incidence of infectious complications after receiving alemtuzumab as part of a conditioning regimen for allogeneic hematopoietic stem cell transplantation (HSCT) in Korean patients. METHODS: From November 2004 to January 2006, 12 patients who received alemtuzumab-based conditioning regimens for allogeneic HSCT were evaluated retrospectively until death or until the end of the follow-up in July 2007; they were compared with 18 patients who received rabbit anti-thymocyte globulin (ATG)-containing conditioning regimens from January 2002 to January 2006. RESULTS: Post-engraftment infections occurred more frequently in the alemtuzumab recipients than in the ATG recipients; the mean number of infections, excluding cytomegalovirus (CMV) infections, per patient during the follow-up period was 2.6+/-1.4 vs. 1.0+/-0.8 (P=0.003), respectively. Although there was no statistical difference in the cumulative incidence of CMV infection between the 2 groups (91.7% vs. 55.6%, P=0.381), the alemtuzumab recipients had a higher incidence of CMV diseases (41.6% vs. 0%, P=0.0006) and a higher recurrence rate of CMV infection (90.0% vs. 27.3%, P=0.008) than did the ATG recipients, irrespective of the dose of alemtuzumab. Hemorrhagic cystitis (HC) (66.7% vs. 16.7%, P=0.009) and BK virus-associated HC (41.7% vs. 5.6%, P=0.026) developed more frequently in the alemtuzumab recipients. The all-cause mortality rate was not significantly different between the alemtuzumab and the ATG recipients (75% vs. 55.6%, P=0.28). CONCLUSION: Alemtuzumab recipients had a high incidence of CMV disease as well as BK virus-associated HC compared with the ATG recipients. The dose of alemtuzumab should be tailored to patients' risk; in addition, the implementation of the appropriate prophylaxis for CMV and early detection strategies for BK virus are recommended.